(1) Field of the Invention
The present invention relates to a press where clutch performance and brake performance are improved and there is little noise.
(2) Description of the Prior Art
In mechanical presses in general, clutch/brake devices are classified into that of combination type where a clutch disk and a brake disk are mainly constituted as a set, and that of separate type where a clutch device and a brake device are constituted separately. In a clutch/brake device of combination type, timing of the press can be taken mechanically and the brake heating can be made favorable and since a working cylinder, an electromagnetic valve or the like can be used commonly, the device can be manufactured at low cost. Also in a clutch/brake device of separate type, since weight of a rotational part is little and the inertia can be decreased, the stopping performance can be improved.
A clutch/brake device 1 of a press in FIG. 1 shows an example of combination type in the prior art. In FIG. 1, a flywheel 3 is arranged rotatable at one end of a crank shaft 2, and a clutch rotary plate 4 supported to the crank shaft 2 is mounted on the side part of the flywheel 3. Also a brake rotary plate 5 is supported to the end part of the crank shaft 2. The clutch rotary plate 4 and the brake rotary plate 5 are provided with frictional surfaces respectively formed in opposition to each other. A clutch disk 6 with a lining applied thereto is arranged to be pushed to the frictional surface of the clutch rotary plate 5, and a brake disk 7 with a lining applied thereto is arranged to be pushed to the frictional surface of the brake rotary plate 5. The clutch disk 6 is supported to the flywheel 3 and is rotated together with the flywheel 3, and the brake disk 7 is supported to the machine frame 8 and a working cylinder 9 is arranged between the clutch disk 6 and the brake disk 7. The working cylinder 9 is supported to the crank shaft 2, and the clutch disk 6 and the brake disk 7 are moved alternately in pushed state to the respective rotary plates.
Further when air means is introduced the working cylinder 9 pushes the clutch disk 6 to the clutch rotary plate 4 and rotates the crank shaft 2, and when the air means is interrupted the working cylinder 9 stops the rotation of the crank shaft 2.
In the clutch/brake device 1 in the prior art, however, in the state that the clutch disk 6 is rotated together with the flywheel 3, the clutch disk 6 is mounted on the flywheel 3 through a gear or a pin, and the clutch disk 6 can advance or retreat with respect to the flywheel 3. The mounting by the gear system is performed as shown in FIG. 2 so that a ring member 11 mounted on the flywheel 3 and having inner teeth 11a formed at the inner circumferential edge part is meshed with the clutch disk 6 having outer teeth 6a formed throughout the outer circumferential edge part. The mounting by the pin system is performed so that one end of the pin inserted into the clutch disk is fixed to the flywheel. In any case, since the clutch disk 6 can advance or retreat with respect to the flywheel 3, in the case of the pin system, backlash is formed between the inner teeth 11a of the ring member 11 and the outer teeth 6a of the clutch disk 6, and in the case of the pin system, backlash is formed between the pin hole of the clutch disk and the pin. The formation of the backlash not only causes deterioration of the clutch performance, but also in the case that the clutch disk 6 is not pushed to the clutch rotary plate 4, when the clutch disk 6 is rotated together with the flywheel 3, interference is produced between the inner teeth 11a of the ring member 11 and the outer teeth 6a of the clutch disk 6 or between the pin hole of the clutch disk and the pin and noise is generated. Since the noise becomes larger as the backlash becomes larger, this is felt troublesome by the worker operating the press. Therefore it has been required that the noise is made small or eliminated.